AST - Documentation

Constructor

new AST(opt)

Source:

ghast.js, line 88

Parameters:

Name	Type	Description
`opt`	`ASTConf`	an ASTConf object

Members

goDown

Return first (leftmost) child. If this node is a leaf, return self.

Source:

ghast.js, line 190

goLeft

Return leftward sibling. If root, return self.

Source:

ghast.js, line 173

goRight

Return rightward sibling. If root, return self.

Source:

ghast.js, line 179

goUp

Return parent. If root, return self.

Source:

ghast.js, line 185

hasAttributes

True if this node has any attributes.

Source:

ghast.js, line 127

hasTags

True if this node has any tags.

Source:

ghast.js, line 125

image

Return captured syntax as a string.

Source:

ghast.js, line 142

isLeaf

True if this node has no children.

Source:

ghast.js, line 120

isRoot

True if this node has no parent.

Source:

ghast.js, line 118

isStem

True if this node is not a leaf or root.

Source:

ghast.js, line 122

leftmostLeaf

Return leftmost descendant node. If this node is a leaf it will return itself.

Source:

ghast.js, line 163

leftmostNode

Return leftmost child node or null if this node has no children.

Source:

ghast.js, line 151

rightmostLeaf

Return rightmost descendant node. If this node is a leaf it will return itself.

Source:

ghast.js, line 154

rightmostNode

Return rightmost child node or null if this node has no children.

Source:

ghast.js, line 149

Methods

ancestor(traverseopt, callbackopt) → {Nodes}

Traverse this nodes ancestors. Same as calling each with up specified.

Source:

ghast.js, line 320

Parameters:

Name	Type	Attributes	Description
`traverse`	`TraverseLike`	<optional>	A Traverse literal
`callback`	`eachNode`	<optional>	A function to be called on the selected node, if any

Returns:

Type:: Nodes

An array of selected nodes, or a single node if first or last are specified. Returns null if first or last are specified and nothing was selected.

Example

// select any 'A' ancestors
node.ancestor('A')
// same as above
node.each({id: 'A', up: true})

attr(a, b) → {ast}

Assign an attribute

Source:

ghast.js, line 430

Parameters:

Name	Type	Description
`a`	`string` \| `Object`	the key to assign, or an object to merge with the nodes attributes
`b`	`*`	the value to assign to key `a`

Returns:

Type:: ast

Returns this node

climb(nopt, callbackopt) → (nullable) {AST}

Return the nth parent node.

Source:

ghast.js, line 336

Parameters:

Name	Type	Attributes	Default	Description
`n`	`number`	<optional>	0	ancestor to select
`callback`	`eachNode`	<optional>		A function to be called on the selected node, if any

Returns:

Type:: AST

The selected node or null if nothing was selected

Example

// return third ancestor
node.climb(2)
// same as above
node.each({up: true, last: true, depth: 2})

each(traverseopt, callbackopt) → {Nodes}

Perform a single traversal of the tree.

Source:

ghast.js, line 247

Parameters:

Name	Type	Attributes	Description
`traverse`	`TraverseLike`	<optional>	A Traverse literal
`callback`	`eachNode`	<optional>	A function to be called on each selected node

Returns:

Type:: Nodes

An array of selected nodes, or a single node if first or last are specified. Returns null if first or last are specified and nothing was selected.

Example

node.each()                       // return all descendants of `node`
node.each({self: true})           // return `node` and all of its descendants
node.each('Section')              // return all descendants with id `Section`

first(traverseopt, callbackopt) → (nullable) {AST}

Return the first descendant selected by the given traverse. Same as calling each with first specified.

Source:

ghast.js, line 303

Parameters:

Name	Type	Attributes	Description
`traverse`	`TraverseLike`	<optional>	A Traverse literal
`callback`	`eachNode`	<optional>	A function to be called on the selected node, if any

Returns:

Type:: AST

The selected node or null if nothing was selected

Example

// select first 'A' node
node.first('A')
// same as above
node.each({id: 'A', first: true})

hasTag(…tags) → {boolean}

Returns true if the node has all of the given tags.

Source:

ghast.js, line 133

Parameters:

Name	Type	Attributes	Description
`tags`	`string`	<repeatable>	zero or more tags to check

Returns:

Type:: boolean

loc(data) → {AST}

Set location data for this node

Source:

ghast.js, line 467

Parameters:

Name	Type	Description
`data`	`Object`	location data to be assigned

Returns:

Type:: AST

Returns this node

match(…query) → {boolean}

Match this node against multiple queries

Source:

ghast.js, line 345

Parameters:

Name	Type	Attributes	Description
`query`	`QueryLike`	<repeatable>	one or more QueryLikes to match against

Returns:

Type:: boolean

Returns true if any of the queries match

mutate(opt) → {AST}

Mutate this node in place, replacing any of its properties with those specified in the config object

Source:

ghast.js, line 400

Parameters:

Name	Type	Description
`opt`	`ASTConf`	an ASTConf object

Returns:

Type:: AST

Returns the new replacement node

read(k) → {*}

Merge the attributes of this node with all of its descendant nodes, and return the value of k

Source:

ghast.js, line 441

Parameters:

Name	Type	Description
`k`	`string`	the key to read

Returns:

Type:: *

The value of k

remove(nopt)

Remove a child node n. If n is not given, remove this node. with those specified in the config object

Source:

ghast.js, line 410

Parameters:

Name	Type	Attributes	Description
`n`	`AST`	<optional>	an AST node

replace(a, bopt) → {AST}

Replace child node a with node b If b is not given, replace self with a

Source:

ghast.js, line 379

Parameters:

Name	Type	Attributes	Description
`a`	`AST`		the child node to replaced, or the node to replace self with
`b`	`AST`	<optional>	the node to replace child node `a` with

Returns:

Type:: AST

Returns the replacement node

select(…traverseopt, callbackopt) → {Array.<AST>}

Perform selections on the tree from a sequence of traversals. Returns the selected nodes if no callback is given.

Source:

ghast.js, line 213

Parameters:

Name	Type	Attributes	Description
`traverse`	`TraverseLike`	<optional> <repeatable>	Zero-or-more Traverse literals
`callback`	`eachNode`	<optional>	A function to be called on each selected node

Returns:

Type:: Array.<AST>

An array of any AST nodes that were selected

Example

// similar to the css selector `A .foo > B`
node.select('A', {tag: 'foo'}, {id: 'B', depth: 0})

tag(…tags) → {AST}

Assign one or more tags

Source:

ghast.js, line 449

Parameters:

Name	Type	Attributes	Description
`tags`	`Tags`	<repeatable>	one or more tags to assign

Returns:

Type:: AST

Returns this node

when(…visitors)

Walk the tree and match each node against the given visitors. When a visitor matches a node its callback is called with the node. Multiple visitors may match each node.

Source:

ghast.js, line 363

Parameters:

Name	Type	Attributes	Description
`visitors`	`VisitorLike`	<repeatable>	One-or-more Visitor literals, or Visitor objects

Example

node.when(
  ['A', 'B', n=> n.foo()],
  [{id: 'C', tag: 'x y'}, {tag: 'c'}, n=> n.bar()],
  [{id: 'Y', leaf: true}, {id: 'Z', leaf: true}, n=> n.baz()],
)